Patents by Inventor Christopher W. Smelser
Christopher W. Smelser has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 8402789Abstract: A method of producing a thermally stable grating allows the grating to be placed in environments where temperatures reach 1000° C. These gratings may be concatenated so as to form a sensor array. The method requires a step of lowering the characteristic intensity threshold of a waveguide by at least 25%, followed by irradiating the waveguide with femtosecond pulses of light having a sufficient intensity and for a sufficient duration to write the grating so that at least 60% of the grating remains after exposures of at least 10 hours at a temperature of at least 1000° C. Pre-writing a Type I grating before writing a minimal damage Type II grating lowers the characteristic threshold of the waveguide so that a stable low damage type II grating can be written; alternatively providing a hydrogen or deuterium loaded waveguide before writing the grating lowers the characteristic threshold of the waveguide.Type: GrantFiled: August 23, 2012Date of Patent: March 26, 2013Assignee: Her Majesty the Queen in Right of Canada, as Represented by the Minister of Industry, Through the Communications Research Centre CanadaInventors: Christopher W. Smelser, Stephen J. Mihailov, Dan Grobnic, Ping Lu, Robert B. Walker, Gino Cuglietta, Huimin Ding, Xiaoli Dai
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Publication number: 20120324959Abstract: A method of producing a thermally stable grating allows the grating to be placed in environments where temperatures reach 1000° C. These gratings may be concatenated so as to form a sensor array. The method requires a step of lowering the characteristic intensity threshold of a waveguide by at least 25%, followed by irradiating the waveguide with femtosecond pulses of light having a sufficient intensity and for a sufficient duration to write the grating so that at least 60% of the grating remains after exposures of at least 10 hours at a temperature of at least 1000° C. Pre-writing a Type I grating before writing a minimal damage Type II grating lowers the characteristic threshold of the waveguide so that a stable low damage type II grating can be written; alternatively providing a hydrogen or deuterium loaded waveguide before writing the grating lowers the characteristic threshold of the waveguide.Type: ApplicationFiled: August 23, 2012Publication date: December 27, 2012Applicants: the Communications Research Centre CanadaInventors: Christopher W. Smelser, Stephen J. Mihailov, Dan Grobnic, Ping Lu, Robert B. Walker, Gino Cuglietta, Huimin Ding, Xiaoli Dai
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Patent number: 8272236Abstract: A method of producing a thermally stable grating allows the grating to be placed in environments where temperatures reach 1000° C. and where the grating is relatively stable and has very low loss from scatter. These gratings have spectral characteristics that allow them to be concatenated so as to form a sensor array. The method requires a step of lowering the characteristic intensity threshold of a waveguide by at least 25%, followed by irradiating the waveguide with femtosecond pulses of light having a sufficient intensity and for a sufficient duration to write the grating so that at least 60% of the grating remains after exposures of at least 10 hours at a temperature of at least 1000° C.Type: GrantFiled: June 18, 2009Date of Patent: September 25, 2012Assignee: Her Majesty the Queen in right of Canada, as represented by the Minister of Industry, through the Communications Research Centre CanadaInventors: Christopher W. Smelser, Stephen J. Mihailov, Dan Grobnic, Ping Lu, Robert B. Walker, Gino Cuglietta, Haimin Ding, Xiaoli Dai
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Patent number: 7689087Abstract: A method of inducing birefringence in an optical waveguide is disclosed wherein the waveguide cladding is irradiated with energy of a sufficient intensity so as to induce a stress in the optical waveguide so as to cause a multitude of spaced stress induced regions within the cladding of the optical waveguide such that there are 10 to 5000 spaced regions per mm and wherein the stress induced regions are proximate the core greater than 2 microns distance from the core-cladding interface. This waveguide has numerous uses, for example a fiber sensor.Type: GrantFiled: July 9, 2008Date of Patent: March 30, 2010Assignee: Her Majesty the Queen in right of Canada, as represented by the Minister of Industry, Through the Communications Research Centre CanadaInventors: Stephen J. Mihailov, Dan Grobnic, Christopher W. Smelser, Robert B. Walker, Ping Lu, Xiaoli Dai, Huimin Ding, Gino Cuglietta
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Publication number: 20090317928Abstract: A method of producing a thermally stable grating allows the grating to be placed in environments where temperatures reach 1000° C. and where the grating is relatively stable and has very low loss from scatter. These gratings have spectral characteristics that allow them to be concatenated so as to form a sensor array. The method requires a step of lowering the characteristic intensity threshold of a waveguide by at least 25%, followed by irradiating the waveguide with femtosecond pulses of light having a sufficient intensity and for a sufficient duration to write the grating so that at least 60% of the grating remains after exposures of at least 10 hours at a temperature of at least 1000° C.Type: ApplicationFiled: June 18, 2009Publication date: December 24, 2009Inventors: Christopher W. Smelser, Stephen J. Mihailov, Dan Grobnic, Ping Lu, Robert B. Walker, Gino Cuglietta, Haimin Ding, Xiaoli Dai
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Patent number: 7567734Abstract: An optical sensor for sensing information relating to an analyte liquid or gas, has a a planar substrate having a refractive index nc. The planar substrate supports a ridge waveguide having an unclad top portion having a refractive index nr. The substrate serves as cladding layer for the ridge waveguide at a location where the ridge waveguide contacts the substrate. A Bragg grating inscribed in the ridge waveguide has two modes for providing information relating to both temperature and refractive index of the surrounding analyte liquid or gas. A cladding mode has a different response to the analyte when compared to a Bragg resonance response. Both modes have a same reaction to temperature, wherein said Bragg grating is formed within the unclad region of ridge waveguide, wherein nc.<nr. Advantageously multiple parameters can be sensed using only a single Bragg grating.Type: GrantFiled: August 8, 2008Date of Patent: July 28, 2009Assignee: Her Majesty the Queen in right of Canada, as represented by the Minister of Industry, through the Communications Research Centre CanadaInventors: Xiaoli Dai, Stephen J. Mihailov, Robert B. Walker, Chantal Blanchetiere, Claire Callender, Huimin Ding, Ping Lu, Dan Grobnic, Christopher W. Smelser, Gino Cuglietta
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Patent number: 7515792Abstract: A method of increasing the refractive index in a photosensitive glass is disclosed so as to induce an refractive index change of at least 10?5 within a region of the glass. The method includes the step of providing a hydrogen or deuterium loaded doped glass material wherein a dopant within the glass is photosensitive to infrared radiation in the presence of hydrogen or deuterium. The hydrogen or deuterium loaded doped glass is subsequently irradiated with femtosecond pulses of infrared light having an intensity of at least 109 W/cm2 and less than 5×1013 W/cm2.Type: GrantFiled: March 7, 2007Date of Patent: April 7, 2009Assignee: Her Majesty the Queen in Right of Canada as Represented by the Minister of Industry, Through the Communications Research Centre CanadaInventors: Stephen J. Mihailov, Christopher W. Smelser, Dan Grobnic, Robert B. Walker, Ping Lu, Huimin Ding, Gino Cuglietta, Xiaoli Dai
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Publication number: 20090041405Abstract: An optical sensor for sensing information relating to an analyte liquid or gas, has a a planar substrate having a refractive index nc. The planar substrate supports a ridge waveguide having an unclad top portion having a refractive index nr. The substrate serves as cladding layer for the ridge waveguide at a location where the ridge waveguide contacts the substrate. A Bragg grating inscribed in the ridge waveguide has two modes for providing information relating to both temperature and refractive index of the surrounding analyte liquid or gas. A cladding mode has a different response to the analyte when compared to a Bragg resonance response. Both modes have a same reaction to temperature, wherein said Bragg grating is formed within the unclad region of ridge waveguide, wherein nc<nr. Advantageously multiple parameters can be sensed using only a single Bragg grating.Type: ApplicationFiled: August 8, 2008Publication date: February 12, 2009Inventors: Xiaoli Dai, Stephen J. Mihailov, Robert B. Walker, Chantal Blanchetiere, Claire Callender, Huimin Ding, Ping Lu, Dan Grobnic, Christopher W. Smelser, Gino Cuglietta
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Patent number: 7483615Abstract: Fiber Bragg gratings were written in pure silica photonic crystal fibers and photonic crystal fiber tapers with 125 fs, 800 nm IR radiation. High reflectivites were achieved with short exposure times in the tapers. Both multimode and single mode grating reflections were achieved in the fiber tapers. By tapering the photonic crystal fibers scattering that would otherwise have occurred was lessened and light external to the fiber could reach the core effectively to write a grating.Type: GrantFiled: February 26, 2007Date of Patent: January 27, 2009Assignee: Her Majesty the Queen in Right of Canada as represented by the Minister of Industry, through the Communications Research Centre CanadaInventors: Stephen J. Mihailov, Dan Grobnic, Huimin Ding, Robert B. Walker, Christopher W. Smelser, Ping Lu, Xiaoli Dai, Gino Cuglietta
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Publication number: 20080310789Abstract: A method of inducing birefringence in an optical waveguide is disclosed wherein the waveguide cladding is irradiated with energy of a sufficient intensity so as to induce a stress in the optical waveguide so as to cause a multitude of spaced stress induced regions within the cladding of the optical waveguide such that there are 10 to 5000 spaced regions per mm and wherein the stress induced regions are proximate the core greater than 2 microns distance from the core-cladding interface. This waveguide has numerous uses, for example a fiber sensor.Type: ApplicationFiled: July 9, 2008Publication date: December 18, 2008Inventors: Stephen J. Mihailov, Dan Grobnic, Christopher W. Smelser, Robert B. Walker, Ping Lu, Xiaoli Dai, Huimin Ding, Gino Cuglietta
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Publication number: 20070201802Abstract: Fiber Bragg gratings were written in pure silica photonic crystal fibers and photonic crystal fiber tapers with 125 fs, 800 nm IR radiation. High reflectivites were achieved with short exposure times in the tapers. Both multimode and single mode grating reflections were achieved in the fiber tapers. By tapering the photonic crystal fibers scattering that would otherwise have occurred was lessened and light external to the fiber could reach the core effectively to write a grating.Type: ApplicationFiled: February 26, 2007Publication date: August 30, 2007Inventors: Stephen J. Mihailov, Dan Grobnic, Huimin Ding, Robert B. Walker, Christopher W. Smelser, Ping Lu, Xiaoli Dai, Gino Cuglietta
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Patent number: 6993221Abstract: A novel method and apparatus for varying the index of refraction of a material using an interference pattern is disclosed. The method and apparatus incorporate an ultra short duration pulse laser source. Electromagnetic radiation provided from the laser propagates to a diffractive element positioned in close proximity to the target material. The diffracted electromagnetic radiation forms an interference pattern, the peaks of which are sufficiently intense to cause a change in index of refraction.Type: GrantFiled: August 13, 2003Date of Patent: January 31, 2006Assignee: Her Majesty the Queen in right of Canada, as represented by the Minister of IndustryInventors: Stephen J. Mihailov, Christopher W. Smelser, Ping Lu, Robert B. Walker, Dan Grobnic, Huimin Ding, George Henderson, Xiaoli Dai
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Publication number: 20040184731Abstract: A novel method and apparatus for varying the index of refraction of a material using an interference pattern is disclosed. The method and apparatus incorporate an ultra short duration pulse laser source. Electromagnetic radiation provided from the laser propagates to a diffractive element positioned in close proximity to the target material. The diffracted electromagnetic radiation forms an interference pattern, the peaks of which are sufficiently intense to cause a change in index of refraction.Type: ApplicationFiled: August 13, 2003Publication date: September 23, 2004Inventors: Stephen J. Mihailov, Christopher W. Smelser, Ping Lu, Robert B. Walker, Dan Grobnic, Huimin Ding, George Henderson, Xiaoli Dai